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| author | Suren Baghdasaryan <surenb@google.com> | 2024-01-12 04:39:35 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-01-13 02:20:49 +0300 |
| commit | 5d4747a6cc8e78ce74742d557fc9b7697fcacc95 (patch) | |
| tree | 8e459befcdcd7ff84cdb2e7a582198a46182ff12 /lib | |
| parent | aa8f91910bf5fb11dcd176e6efac2dbe2cecebea (diff) | |
| download | linux-5d4747a6cc8e78ce74742d557fc9b7697fcacc95.tar.xz | |
userfaultfd: avoid huge_zero_page in UFFDIO_MOVE
While testing UFFDIO_MOVE ioctl, syzbot triggered VM_BUG_ON_PAGE caused by
a call to PageAnonExclusive() with a huge_zero_page as a parameter.
UFFDIO_MOVE does not yet handle zeropages and returns EBUSY when one is
encountered. Add an early huge_zero_page check in the PMD move path to
avoid this situation.
Link: https://lkml.kernel.org/r/20240112013935.1474648-1-surenb@google.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Reported-by: syzbot+705209281e36404998f6@syzkaller.appspotmail.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
0 files changed, 0 insertions, 0 deletions